EasyJet has apologised after passengers accused the airline of "abandoning them without food or water".One flier, a 70-year-old retired psychology lecturer, accused the airline of leaving him and fellow travellers stranded at Montenegro's Tivat Airport for more than 24 hours with no provisions or airline staff on hand to assist them.Dr Ron Roberts, who was attempting to return to the UK, alleged the budget carrier effectively deserted its passen…